Robust stabilization of ship course by convex optimization

For ship course control, this paper presents a novel nonlinear controller design method using the sum of squares (SOS) technique combined with the dual of Lyapunov´s stability theorem based on density function. Varying load condition and ship speed are seen as uncertainty, and then the robust nonlinear controller is also designed based on the suggested method. Simulations are performed by taking ocean-going ship model as an example.